Defines operators for different types of search fields

<div class="definition">
    Object, default = {...} // see below
</div>

This operators are used for different type of search fields. Default operators are:

<textarea class="javascript">
{
    'text'    : ['is', 'begins', 'contains', 'ends'], // could have "in" and "not in"
    'number'  : ['=', 'between', '>', '<', '>=', '<='],
    'date'    : ['is', 'between', { oper: 'less', text: 'before'}, { oper: 'more', text: 'after' }],
    'list'    : ['is'],
    'hex'     : ['is', 'between'],
    'color'   : ['is', 'begins', 'contains', 'ends'],
    'enum'    : ['in', 'not in']
}
</textarea>
All possible operators are:
<ul>
    <li><b>is</b> - same as =</li>
    <li><b>begins</b> - for text only</li>
    <li><b>contains</b> - for text only</li>
    <li><b>ends</b> - for text only</li>
    <li><b>more</b> - same as ></li>
    <li><b>less</b> - same as <</li>
    <li><b>=, >, >=, <, <=</b> - for numbers and dates</li>
    <li><b>between</b> - for numbes and dates</li>
    <li><b>in</b> - for sets</li>
    <li><b>not in</b> - for sets</li>
    <li><b>null</b></li>
    <li><b>not null</b></li>
</ul>

<h4>See Also</h4>

<a href="w2grid.operatorsMap">operatorsMap</a> - map of search type to oeprators<br>
<a href="w2grid.defaultOperator">defaultOperator</a> - default operator for each search type<br>
